Effects of Autologous Conditioned Plasma® (ACP) on the healing of surgically induced core lesions in equine superficial digital flexor tendon

Abstract

Summary: Tendon pathologies are among the most common musculoskeletal disorders in horses. After damage the tendon repairs by forming disorganized scar tissue that is of inferior functional quality than normal tendon, leading to high re-injury rates. Many of the currently available treatment modalities cannot significantly reduce this high recurrence rate. Autologous Conditioned Plasma (ACP, Arthrex Inc., USA) has been described in the literature as a leukocyte-reduced platelet concentrate. This blood product has been used in equine and human medicine for the treatment of tendon and ligament injuries. However, the effect of this therapeutical approach on tendon healing is unknown. Core lesions were surgically induced in the Superficial Digital Flexor Tendons (SDFT) of both fore-and hindlimbs in eight healthy horses. At days 7 and 15 after lesion induction one randomly assigned fore-and hindlimb was treated with ACP and the contralateral one with saline. This study used data from the forelimbs SDFTs only. Gray-scale and color Doppler ultrasonographic parameters monitored throughout the study did not differ significantly at any time point. 22 weeks after the last treatment, the ACP treated tendons presented a significantly lower concentration of sulphated glycosaminoglycans (GAGs) (p ≤ 0.05) when compared to saline. Other compositional, biomechanical and histological parameters presented no significant differences. Our study indicates that 2 intra-tendinous ACP treatments (without anticoagulant) during the proliferative phase of healing in surgically induced tendon core lesions have a limited effect on tendon healing when comparing ultrasonographic, biochemical, biomechanical and histological parameters with the control treatment. Long-term placebo controlled clinical trials with more horses are warranted to determine if this effect is clinically significant.Keywords: horse / platelet concentrate / Autologous Conditioned Plasma (ACP) / tendon / healing / model / orthopedics Auswirkungen von Autologous Conditioned Plasma ® (ACP) in der Heilung von chirurgischen induzierten Kernläsionen der oberflächlichen Beugesehne des Pferdes Sehnenerkrankungen gehören zu den häufigsten Erkrankungen des Bewegungsapparates beim Pferd. Nach einer Läsion werden die Sehnen in der Regel durch unorganisierte Bildung von Narbengewebe repariert. Die reparierten Strukturen zeigen eine niedrige funktionale Qualität, was zu einer hohen Wiederverletzungsrate führt. Viele der derzeit verfügbaren Behandlungsmethoden können diese hohe Rezidivrate nicht reduzieren, was eine Fortsetzung der Suche nach verbesserten Therapien vorantreibt. Autologous Conditioned Plasma ® (ACP, Arthrex Inc., USA) ist in der Literatur als ein leukozytenreduziertes Thrombozytenkonzentrat beschrieben worden, welches zur Behandlung von Sehnen-und Bänderverletzungen in der Pferd -und Humanmedizin verwendet wurde. Jüngste Studien deuten an, dass diese Therapieform die Sehnenheilung effektiver als andere Thrombozytenkonzentrate fördern könnte. Allerdings ist der Effekt dies...

Effect of intralesional platelet-rich plasma (PRP) treatment on clinical and ultrasonographic parameters in equine naturally occurring superficial digital flexor tendinopathies – a randomized prospective controlled clinical trial

“…However, it cannot be excluded that PRP injection effectively induced a transient inflammatory response [29, 83] which might have contributed to a temporary decrease in echogenicity and in alignment of fibrous structures. This contrasts with results of an experimental equine study showing no differences at all for several B-mode parameters between SDFTs treated with a leucocyte poor single centrifugation plasma product and saline [84]. Although echogenicity and fiber alignment scoring using B-mode ultrasonograms are established tools in clinical settings, they have a limited sensitivity to adequately reflect tendon intergrity [35].…”

Effect of single intralesional treatment of surgically induced equine superficial digital flexor tendon core lesions with adipose-derived mesenchymal stromal cells: a controlled experimental trial

“…On the other hand, an increased GAG content as expressed per DNA has been interpreted as a sign of improved tendon healing in a recent equine study after intralesional platelet-rich plasma (PRP) treatment [45]. Interestingly, GAG contents of saline-treated control tendons in the latter study and in another study testing a plasma product [79] were similar to the GAG content in both groups of the current study using the same surgical model of tendinopathy, respectively. This also corresponds well to findings in naturally injured SDFTs that were saline treated and contained significantly more GAG than corresponding BM-MSC-treated as well as untreated control tendons, which were relatively uninjured [13].…”

Comparison of healing in forelimb and hindlimb surgically induced core lesions of the equine superficial digital flexor tendon

“…This study was part of a larger research project in which the effect of an autologous platelet concentrate on tendon healing was compared to saline control (18). The present study used data derived from salinetreated fore-and hindlimb SDFT lesions only.…”